Amphibious transport dock ships are warships that embark, transport, and land elements of a landing force for a variety of expeditionary warfare missions. Amphibious transport docks are used to transport and land Marines, their equipment and supplies by embarked Landing Craft Air Cushion or conventional landing craft and Amphibious Assault Vehicles augmented by helicopters or vertical take off and landing aircraft. These ships support amphibious assault, special operations or expeditionary warfare missions and can serve as secondary aviation platforms for amphibious ready groups.